A police chief has said she is "profoundly sorry" for the lack of support given to the family of a teenage boy who drowned after going swimming.

The body of 16-year-old Ellis Downes was recovered from the River Thames late on Monday night by volunteer divers who responded to an appeal by his family, who said Thames Valley Police had failed to get their own divers to the scene.

The teenager from Harwell had not been seen since going swimming in the River Thames at Culham two days earlier.

In a video message, Thames Valley Police Assistant Chief Constable Nikki Ross said: "I am profoundly sorry for the treatment of the Downes family over the weekend, in particular the level of support, the level of compassion, the lack of information and communication that we afforded them, and in particular Mr and Mrs Downes and Ellis's two sisters.

"This fell far below the standards that we would expect from our staff and I apologise for that."

Ellis's sister Alex had appealed online for volunteers to help in the search last weekend, claiming police had begun to scale back their operation due to a lack of resources.

Thames Valley Police referred itself to the Independent Police Complaints Commission on Wednesday following "family and community concerns" around the investigation.

Ms Ross continued: "As a mother myself I cannot begin to understand the distress that the family is feeling but I would expect more care and compassion to be shown to people in these circumstances.

"Our action and our inactions will be subject of a thorough investigation and we have referred ourselves to the Independent Police Complaints Commission to ensure that that's done.

"Once again I'm profoundly sorry and apologise on behalf of Thames Valley Police for any added distress that we have caused to the family at this very difficult time."

Miss Downes said the police apology was "a start".

In a Facebook post, she said: "Glad that the police made the first step by admitting they had done us wrong by referring themselves to the IPCC.

"This public apology is the least we expected; we know, of course, an apology is never going to bring Ellis back, but it's a start. Words mean nothing without actions though.

"All we want now is for things to change about the way TVP handle operations so that we can prevent this happening again in the future, then hopefully, thanks to Ellis, no family will have to go through this ever again."